In cognitive radio network, secondary (unlicensed) users (SUs) are allowed to utilize the licensed spectrum when it is not used by the primary (licensed) users (PUs). Because of the dynamic nature of cognitive radio network, the activities of SUs such as “how long to sense” and “how long to transmit” significantly affect both the service quality of the cognitive radio networks and protection to...

Performance evaluation and analysis are of key importance to obtain deep understanding of cognitive radio networks. Some effects have been made to model and analyze the performance of cognitive radio networks. In the literature, there are two methodologies: queuing theory/Markov chain-based analysis and stochastic network calculus-based analysis. These two methodologies rely on different mathem...

The deployment of Cognitive Radio Networks has been greatly hindered in spite of its potentials by the rate at which intrusions and vulnerabilities replicate within every domain of the network. Cognitive Radio Network is expected to drive the next generation wireless networks that can optimize the use of spectrum due to its unique and dynamic properties, but the high rate of intrusions has frus...

1. INTRODUCTION Public Access Mobile Radio systems (PAMR) using trunking technology allow more efficient use of the frequency spectrum, as all the users of the system jointly use a common pool of channels. This counteracts one of the limiting factors on the growth of conventional Private Mobile Radio systems (PMR), frequency congestion [1]. Moreover the public trunked network offers the user ma...

munications have posed a challenge. The first major improvement was the megaphone or speaking trumpet, which allowed an officer with a decent set of lungs to yell orders to firefighters over the din of the fireground. The first truly portable radios were introduced in the early 1960s, and firefighting took on a new dimension. Officers could command the fireground with radios and communicate bot...

Network technology based on the Internet Protocol has now advanced to the point that data traffic of any kind can be as reliably transported via Ethernet as it can via TDM. This paper explores the strengths and weaknesses of both TDM and Ethernet transport within the context of microwave radio communications. The paper further describes the operational advantages of Ethernet and Ethernet radio ...

Radio network planning for UMTS technology is a relevant task for operators in the current roll-out phase. We recall a mathematical mixed-integer programming model for planning cost-efficient radio networks under network quality constraints. Based on this model, we present network planning methods. Computational results are given for two large-scale, realistic scenarios, and we compare the mixe...

This is a speci cation for the network architecture and functionality of the Rapidly Deployable Radio Network. Invariants for each protocol layer, as well as con guration, recon guration, link quality, and mobility are speci ed. Implementation of high level functionality is prioritized, while refraining from over-specifying some of the interesting areas of research. Existing standards and areas...

In this research paper a technique is introduced to improve Bit Error Rate in cognitive radio. In this paper the FHSS of 32-bit and DSSS of 16-bit is implemented in the network. After implementation of proposed technique results are produced which shown that the proposed approach is far better than that of existing work to reduce BER in a network. Network consists of both wired and wireless top...